In wireless communication systems, QoS (Quality of Service) management has been performed based on simple classification of generated traffics. For example, for QoS management, traffics are classified into voice, video, best-effort, background, etc. Such a simple classification of traffic is likely that user's intentions are not reflected on the whole. For example, when a user device receives an e-mail from an e-mail server, there may be a case where an e-mail client checks new e-mails periodically on a predetermined time basis, while there may be another case where the e-mail client checks new e-mails in accordance with a user's refresh command. In aspect of data traffic, both of two cases cannot be distinguished because for the e-mail server, both are refresh requests on e-mail.